4. Researchers at the University of Michigan developed a drone that can autonomously nail asphalt shingles to a roof. The prototype is equipped with a professional-grade nail gun and relies on a system of location markers and video cameras to "know" where to drive each nail. Gizmodo notes that it's still not as fast as a professional roofer and has only 10 minutes of flight time, though a cable tether could fix that. Last month, the Federal Aviation Administration issued a warning against attaching weapons, including nail guns, to drones. - GIZMODO